Methods for producing cyclic phenol sulfides include the method which comprises the steps of using a phenol compound, sulfur and an alkali metal reagent as raw materials and synthesizing them by heating (for example, see Patent Literatures 1-2, and Non-patent Literature 1). These methods are easy and practical production methods wherein the objects can be obtained in one operation and an inexpensive raw material is used. However, the distribution of the products tends to be focused in a cyclic quatromer wherein m=4 in the formula (2). Besides it, when obtaining more macrocyclic products wherein m=5 to 9 in the formula (2), the collection of a cyclic quartromer is not taken account, and the overall yield is not considered. In the purification process, column chromatography is required. Further, there is the method which comprises the steps of using a chain phenol sulfide, sulfur and an alkali metal reagent as raw materials and synthesizing them by heating (for example, see Patent Literatures 3 to 6). Though these methods make it possible to produce a number of more macrocyclic products wherein m=5 to 9 in the formula (2), the yield of a cyclic quatromer becomes less. In addition, the methods comprise two steps, that is, the step of producing a chain phenol sulfide from a phenol compound, and the step of cyclizing the chain phenol sulfide to produce a cyclic phenol sulfide. Thus, they are industrially unfit.
Patent Literature 1: JP-A9-227553
Patent Literature 2: JP-A2002-193963
Patent Literature 3: JP-A 10-081680
Patent Literature 4: JP-A 11-049770
Patent Literature 5: JP-A 2000-273096
Patent Literature 6: JP-A 2002-255961
Non-patent Literature 1: H. Kumagai et al., Tetrahedron Lett.(1997), 38, 3971-3972